In a physical vapor deposition (PVD) chamber, a dark space region exists between a powered electrode, such as the sputtering target, and a grounded shield disposed proximate the target's edge, referred to as a dark space shield. In an existing PVD chamber, the dark space shield is typically mounted to the main body of the PVD chamber, separately from the target. The target is typically mounted on a removable lid of the PVD chamber and then lowered onto the chamber body for processing. However, the inventors have discovered that such a configuration may undesirably result in the dark space shield and the target being inaccurately aligned.
The inventors have further discovered that as the frequency of radio frequency (RF) energy applied to the target increases, the dark space region becomes more critical to controlling any plasma irregularity and arc events, which may negatively affect the quality of deposition in the PVD chamber.
Accordingly, the inventors have provided improved apparatus for PVD processing.